find out why the UK variant is up to 70% more contagious

Scientists were able to identify where the Covid-19, in its process of “copying” itself, would have made the “mistake” that resulted in a much more contagious variant which has spread to much of the world. The British variant, which was first detected in September, is believed to have appeared in the Duchy of Kent, in a patient with a disease that compromised his immune system. For this reason, he had an extremely prolonged clinical picture, during this time a series of changes in the SARS-CoV-2 genome and, from this zero case, the chain of infections was started.

Although it is difficult to confirm 100%, this variant would have appeared which has spread to around a hundred countries including Argentina – where it has community circulation – forced a confinement in Great Britain already suspension of flights. What science has more certainty now is why this variant is between 50% and 70% more transmissible than the original from Wuhan. And to the surprise of the researchers, the key to increased transmissibility appears to be not only an increased willingness to bind to the human cell’s receptor, but the dynamics with which it is reproduced inside once you enter.

The research carried out by specialists at the prestigious Mount Sinai School of Medicine in New York is so recent that it has not yet been published in a scientific journal. But it is shared by the technical scientific director of ANLIS-Malbrán, an Argentinian scientific body which tirelessly follows the course of the pandemic and which has a strategic collaboration with the American entity.

The British variant has 23 mutations of which 8 are in the spicule. Among these, there is one in particular which would give the virus more affinity to bind to the AC2 receptor in the human cell. It was believed that this was the reason why this variant is so much more contagious, but now we know that This is not the only one.

“These mutations give the virus much greater replication kinetics. We now know that three hours after the virus enters the human cell, the number of copies is equal to that between 24 and 48 in the variant which was circulating at that time. Its replication dynamic is extremely faster and if you have more viral load, you will spread more”, Explains geneticist Claudia Perandones.

Expert ANLIS-Malbrán says that these same mechanisms have been analyzed in the other three VOCs, acronym in English for the worrisome variants, which are followed with particular attention: South Africa, Manaus and Rio de Janeiro (the latter two were also detected here). And they found that although they have a replication dynamic greater than the wild type (the original virus), does not match UK. “Knowing the advantages that these variants bring to the virus allows us to generate much more targeted therapeutic strategies. If you have the difference in viral load is very close to the start of the table, you need to exacerbate early diagnosis and isolation», Says Perandones, and asks« not to be afraid of the variants ».

In this sense, it addresses an issue that has recently aroused concern in the scientific community: the identification of two patients in Brazil who had co-infections of two different variants. “The question was asked whether the patients were infected with a variant which, by persisting over time, generated changes that would cause another variant to appear. But genomic studies were done in the population and they found that there were two variants, that of Rio de Janeiro and that of Rio Grande Do Sul, and it was confirmed that they were fine. co-infections of two different variants. They were even able to sectorize in those patients that the upper respiratory tract had an infection with one variant and the lower part with another, such as respect for viral territories. These are two independent events that did not make the clinical picture more serious, ”he reassures.

It also demystifies that SARS-CoV-2 mutate more than other viruses. This is what it may sound like to us, maybe because we are all on hold and no one notices how the flu virus mutates. This is because, in fact, the agent that causes influenza has a mutation rate between 15 and 20 times higher than Covid. Because the virus that holds the whole world in suspense has a mechanism called proofreading (who does not have the flu), which is like a “read” when it replicates and helps control the mistakes you make in generating the copies. Thus, the number of errors or mutations is reduced.

However, there is. And, says Perandones, there always will be. Because all viruses are mutating all the time. In some cases, like in these variants we’re talking about, mutations give them selective advantages, like being more heritable. Encouraging information provided by the expert is that of the three detected here (Rio de Janeiro, Manaus and United Kingdom), convalescent plasmas with a high concentration of antibodies may have neutralize the viral effect. This is not only positive as regards the treatments but it “gives the certainty of the effectiveness of the vaccine”.

Regarding vaccines, he insists, as infectologists have already done, on the fact that pharmaceutical companies are testing the efficacy against the different variants that have appeared so far and that the formulations can be corrected, as is the case with the flu. “Perhaps the situation to be raised is that we won’t have a vaccine development that will last forever“, He says.

And finally, can all of these changes in the virus lead at some point let’s have an argentinian variant? “It is possible. No country in the world can say that it will not have a variant of Covid. That is why it is important to monitor who is circulating and the potential introductions travelers may make. We may have. an Argentinian variant, but maybe not all the variants that emerge will be negative, ”he concludes.

AS